0 p v; o (D a . o- p

0 p v; o (D a . o- p cl n e eat Pfiesteria. The endotoxin is y then passed on in the foodchain 3- to humans when they eat the >e mussels. a Pfiesteria can tolerate a wide range of temperature and salinity, but the fish-kills have occurred in water with a temperature of about 80 degrees Fahrenheit (although it can be toxic from 50 to 95 degrees F.) It thrives in brackish water with salinity of 15 parts per thousand which seems to also bring about the toxic stage (although it can be toxic in fresh water or ocean water which has a salinity of 35 ppt, he said.) Non-Point Pollution' The issue receiving so much press recently is whether it responds to nutrients, Lacouture said. The opinion of the experts is that it does. High g levels of nutrients in the water ? increases the amount of algae and since algae is a food source 1 for Pfiesteria, high levels of y nutrients in the water cause high levels of Pfiesteria. High levels of phosphorous in the water directly affect Pfiesteria when it is in its fish3 killing stage by causing it to reproduce at an accelerated i rate. “In my opinion, nutrients J in the water are a significant 1 factor,” Lacouture said. He thinks major rain f events that occurred several i days before fish kills this sum3 mer were meaningful. In 1996 there was an unusually high t runoff with nutrients being i carried along with it, he said. r The 1997 spring and summer were dry causing the river i water to be “low flow” and I slow-moving, more like a lake than a river and were perfect r conditions for Pfiesteria. He : said he thinks this contributed ; to the incidence of the toxic stage of the organism. When a species of dinoflagellates has a population explosion in a river, estuary or^’ ocean, a dramatic “red tide” ' can be seen. Although usually benign, it can be toxic and dangerous. “What the real mes